Circuit breaker control system



Patented Sept. 7, 1943 CIRCUIT BREAKER CONTROL SYSTEM Maurice E. Reagan and Guy W. Champney,

Pittsburgh, Pa., Electric 85 assignors Manufacturing Company,

to Westinghouse East Pittsburgh, Pa., a corporation of Pennsylvania Application December 16, 1941, Serial No. 423,191

8 Claims.

Our invention relates, generally, to circuit breaker control systems and, more particularly, to control systems embodying anti-pumping means and means for positively closing and latching circuit breakers.

In previously .known circuit breaker closing systems in which a plurality of relays have been employed to close a circuit breaker and have been interconnected to prevent pumping of the breaker, it has been found that the relay system often releases before the circuit breaker latches in closed position, thus resulting in failure of the circuit breaker to positively close and latch.

It is an object of our invention to provide a circuit breaker control system which shall function to so control a circuit breaker as to positively close and latch the breaker, and which shall be simple and efficient in operation and inexpensive to manufacture, install, operate, and maintain.

These and other objects and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawing, in which like reference characters indicate like parts in the several figures, and in which,

Figures 1, 2, and 3 are each a diagrammatic view of a circuit breaker control system embodying the principal features of the invention.

In practicing the invention, in the embodiment of Fig. l, a circuit breaker 4 having a trip-free operating mechanism including a closing coil 6 and a trip coil 8 is shown. A relay it] controls the closing coil 6 and is, in turn, controlled by a relay l2 and a close circuit control device M. The relay I2 is held energized in a circuit which includes a contact element It actuated to open position by the operation of the breaker operating mechanism by the coil 6. A capacitor It is connected in shunt or parallel relation with the winding of the relay I2 to continue the energization of the relay Ill and the closing coil for interval after the breaker has closed, thereby insuring that the breaker will be positively closed and latched before release of the closing coil 8.

The embodiment of the invention shown in Fig. 2 is a circuit breaker control system such as may be employed at automatic stations and has a master relay through which the relays ill and t2, the capacitor l8, and the closing and trip coils 6 and 3 function in a manner similar to the system of Fig. 1.

The system of Fig. 3 is an automatic reclosing System enqbodying the principles of the closing elements of the systems of Figs. 1 and 2, and ineluding an automatic timing means or recloser 22 for preventing the breaker l from reclosing in the event that it trips within a predetermined time after any closure.

Considering the invention more in detail, with reference to Fig. 1, the circuit breaker 4 may be disposed to connect a power bus represented by the conductors 24 and 25 with adistribution line including conductorsit and 39. A source of alernating current control power, represented by the conductors 32 and 34, may be provided. It is to be understood that it is not necessary that the control power be alternating current, and in the event that direct current control pow-er is provided, the rectifiers referred to hereinafter may be omitted and direct connection may be made to the elements of the system to which the rectifiers supply direct current power.

The closing coil 6 of the circuit breaker :1 operates against the bias of a spring member 38 and through engaging detents 33 and 4&1 to move the linkage 42 against the bias of a spring member 4 4 to close the circuit breaker. When the circuit breaker is in closed position, a detent -26 on an arm 58, which actuates the linkage 42, will he engaged by a spring-pressed detent to hold the circuit breaker in closed circuit position. The trip coil 3 of the circuit breaker when energized will function to move the arm 59 downwardly to disengage the detent it from the detent L3 and permit the spring member M to actuate the linkage 42 to move the circuit breaker to open circuit position.

An energizing circuit is provided for the relay I 0 extending from the conductor 32 through conductors 52, 54, and the winding of the relay H3, a conductor 58, a contact element til or" the relay l2, a conductor 62, contact element of the close 0' cult control device 54, and conductors 04 and $6 to the conductor The relay it con trols an energizing circuit for the closing coil 5 of the circuit breaker A which extends from 0011 ductor 32 through the conductors 5'2 and Ei l, a contactelement 68 of the relay ii), a conductor 10, a full-wave rectifier device l2, conductors "i l and i6 connected between the rectifier l2 and the winding of the closing coil 5, and conductors 6i and 66 to the conductor 34.

A normal energizing circuit is provided for the relay I2 and extends from the conductor 32 through the conductor 52, a rectifier 13, a conductor 80, a resistor 82, the winding of the relay I2, conductors 84 and St, a contact element of the circuit control device Hi in back contact position, a conductor 88, a contact element of a trip circuit control device in back contact position, conductors 92 and 94, the contact element I6 actuated by the circuit breaker closing coil 6, and conductors 86, 64, and 66 to conductor 34.

Th relay I2 also controls its own holding circuit extending from the conductor 32 through the conductor 52, th rectifier 18, the conductor 80, the resistor 82, the winding of the relay E2, the conductor 84, a contact element 98 of the relay I2, the conductor 94, the contact element I6, and conductors 96, 64, and 66 to the conductor 34.

A condenser I8 is connected in shunt circuit relation with the winding of the relay I2 and the resistor 82 in a circuit which extends from a terminal of the resistor 82 through the conductor 89, the condenser I8, and conductors 86 and 84 to a terminal of the winding of the relay I2. While the relay I2 is energized, the condenser I8 is also energized and held in charged condition until the energizing circuit for the relay I2 is opened by the movement of the contact element I6 to open circuit position when the closing coil 6 is actuated, at which time the condenser I8 will discharge through the winding of the relay I2 and the resistor 82 to maintain energization of the relay I2 and delay its release for an interval after its energizing circuit is opened.

An energizing circuit for the trip coil 6 extends from the conductor 32 through a conductor I00, a contact element I02 actuated by the circuit breaker 4, a conductor I84, the winding of the trip coil 8, a conductor I06, the contact element of the circuit control device 90 in front contact position, and conductors I08, 64, and 66 to the conductor 34. A voltage responsive or any other suitable protective relay I I is connected to the power bus conductors 24 and 26 to trip the circuit breaker when the potential on the power bus conductors 24 and 26 falls below a predetermined amount. The trip circuit controlled by the relay IIO extends from the conductor 32 through the conductor I50 to contact element I02, the conductor I04, th winding of the trip coil 8, conductors I06 and H2, a contact element I I4 of the relay H0, and conductor 66 to the conductor 34.

In the operation of the system of Fig. 1, the relay I2 will be normally held energized in the circuits hereinbefore described. When it is desired to close the circuit breaker, the close circuit control device I4 may be manually actuated to close the energizing circuit for the relay I which, in turn, will close the energizing circuit for the closing coil '6 of the circuit breaker 4. When the closing coil 6 actuates the circuit breaker to closed position, the contact element I6 will be moved to open circuit position to open the holding circuit for the relay I2. However, the relay I2 will not release immediately but will be held energized by the discharge of the condenser I8 through the winding of the relay I2, thus maintaining the relay I0 and, therefore, the winding of th closing coil 6 energized for an interval of time after the closing coil 6 has actuated the cir cuit breaker 4 to closed position to thereby insure that the circuit breaker will be positively closed and the latch members 46 and 48 will be positively engaged to hold the circuit breaker in closed position before the closing coil 6 is deenergized.

In the embodiment of the invention of Fig. 2, the energizing circuit for the relay I0 extends from the conductor 32 through a conductor I IS, acontact element H8 of the relay I2, a conductor 220, the winding. of the relay I8, conductors I22 and. I24, a contact element I26 of the relay in front contact position, and a conductor I28 to the conductor 34. The rela I0 energizes the winding of the closing coil 6 of the circuit breaker 4 in a circuit which extends from the conductor 34 through the conductor I28, the contact element I26, the conductor I24, the contact element 68 of the relay III, a conductor I29 to the rectifier 12, the conductors 14 and 16 extending between the rectifier 12 and the closing coil 6, and a conductor I 30 to the conductor 32.

An energizing circuit is provided for the relay 20 extending from the conductor 32 through the conductors I3I, I32 and I33, a closed contact element I34, a conductor I36, a contact element I38 of a potential responsive or other suitable protective relay I40 which is connected to the conductors 24 and 26, conductors I42, I44, and I46, the winding of the relay 20, conductors I48 and I50, a resistor I52, a conductor I54, a contact element I56, and a conductor I58 to the conductor 34. The relay 20 controls its own holding circuit extending from the conductor 32 through a conductor I60, 2. contact element I62 of the relay 20, the conductors I42, I44 and I46, the winding of relay 20, conductors I48 and I50, the resistor I52, the conductor I54, the contact element I56, and the conductor I58 to the conductor 34. The relay 20 in deenergized position controls an energizing circuit for the relay I2 extending from the conductor 32 through the conductors I60 and I64, a contact element I66 of the relay 20 in back contact position, a conductor I68, the winding of the relay I2, a resistor I10, a conductor I12, a rectifier 18, and a conductor I14 to the conductor 34.

The relay I2 controls its own holding circuit extending from the conductor 32 through the conductor I3I, the contact element I6, a conductor I16, 2; contact element I18 of the relay I2, conductors I60 and IE8, the winding of the relay I2, the resistor I10, the conductor I12, the rectigiir 18, and the conductor I14 to the conductor An energizing circuit for th trip coil 8 of the circuit breaker 4 is controlled by the contact element I26 of the relay 20 in back contact position in a circuit extending from the conductor 34 through conductors I28 and I82,'the contact element I26, a conductor I84, the winding of the trip coil 8, a conductor I86, the contact element I02 actuated by the circuit breaker 4, and conductors I33, I82, and I3I to the conductor 32.

The relay 20 may be released by a "trip contact element I88 which closes a shunting circuit r for the winding of the relay 20 extending from one terminal of the winding relay 20 through the conductors I46 and I44, the contact element I86, and conductors I50 and I48 to the other terminal of the winding of the relay 20. Another shunting circuit is controlled by the contact element I38 of the voltage responsive relay I40 extending from one terminal of the winding of the relay 20 through the conductors I46 and I44, the contact element I33, and conductors I90, I50, and I48 to the other terminal of the Winding of the relay 20.

It is to be understood that the system of Fig. 2 is such a system as may be employed at a remotely controlled automatic substation, and that the close contact element I34 and the trip" contact element I88 may be contact elements controlled by a supervisory or other control system extending between a control station and the remote station at which the circuit breaker 4 is lo cated.

A contact element I92 controls a relay I94 which is disposed to actuate a detent I96 against the bias of a spring member I98 to move the detent I96 from engagement with a detent 200 which will permit the contact element I56 to be released to move to open circuit position. The energizing circuit for the relay I94 extends from the conductor 32 through a conductor 202, the contact element I92, a conductor 204, the winding of the relay I94, conductors 206 and I 54, the contact element I56, and the conductor I58 to the conductor 34. This release of the contact element I56 will break'the energizing circuits for the relay 20 and will hold the energizing circuit open until the contact element I56 is moved manually back to closed circuit position.

It is to be understood that the contact element I92 which controls the relay I94 may be any contact element moved to closed circuit position by any protective device which is operated by a condition at the substation, which, when it occurs, makes it desirable that the circuit breaker 4 be maintained in open circuit position until the condition is investigated and remedied. Such a condition may be an extremely high bearing temperature on apparatus connected to the conductors 28 and 30 which are fed from the conductors 24 and 26 through the circuit breaker 4. I

In the operation of the system of Fig. 2, when it is desired to put the apparatus at the substation in operation by closing the circuit breaker 4, the contact element I34 will be actuated to closed circuit position, and the energizing circuit for the relay 20 will be completed thereby. When the relay 20 is actuated, its contact element I62 will close the holding circuit for the relay 20, and the contact element I26 of the relay 20 will close the energizing circuit for the relay I0, which, in turn, will close the energizing circuit for the closing coil 6.

When the closing coil 6 is actuated to close the circuit breaker 4, its contact element I6 will move to open circuit position to thereby break the holding circuit for the relay I2. However, the

relay I2 will not release immediately but will be held energized by the discharge of the condenser I8 through the winding of the relay I2. The relay I2, the relay I0, and the closing coil 6 will thereby be maintained energized for a short interval after the closing coil 6 has actuated the circuit breaker to closed circuit position to insure that the circuit breaker is fully actuated to the closed circuit position and that the latch members 46 and 48 are properly engaged to hold the circuit breaker in closed circuit position.

When it is desired to trip the circuit breaker 4, the trip contact element I 88 will be actuated to release the relay 20, and the contact element I26 will cause the tripping coil 8 to b energized, thereby tripping the breaker. When the relay 20 is released, its contact element I66 will energize the relay I2, which, in turn, will close its own holding circuit and thereby remain in actuated position.

The embodiment of the invention of Fig. 3 is a circuit breaker control system which functions to automatically open the breaker in respons to a fault on the conductors 28 and 30 to immediately reclose the breaker, and to prevent the breaker from closing a second time in the event that the breaker fails to remain closed fora predetermined time after the first reclosure.

The timing device or recloser comprises a timing element 201 and a relay element 208. The relay element has a pair of contact elements 209 and 2I0 disposed to be moved to the right-hand position, in which they are shown in the drawing, by a coil 2I2 and to a left-hand position by a coil 2I4, and are adapted to remain in the position to which they are moved by either the coil 2I2 or the coil 2I4.

A close circuit control device 2I6 is disposed to close an energizing circuit for the relay I0 extending from the conductor 32 through a conductor 2I8, the winding of the relay I0, a conductor 220, a contact element 222 of the relay I2, a conductor 224, a contact element 226 which is actuated to closed position by the circuit control device 2I6 and which is mounted on an arm 225 which is adapted to be held in the position to which it is moved by a spring member 221, and conductors 228 and 230 to the conductor 34. The relay [6 when actuated closes an energizing circuit for the closing coil 6 of the circuit breaker 4 which extends from the conductor 34 through a conductor 232, the contact element 58 of the relay I0, a conductor 234, the rectifier 12, conductors 14 and 16 extending between the rectifier 12, and the closing coil 6, and a conductor 236 to the conductor 32. i

The contact element 209 in its right-hand position forms part of a holding circuit for the relay I2 which extends from the conductor 32 through the conductors 238, 239, and 240, the contact element 209, conductors 242 and 244, the rectifier 18, a conductor 245, a resistor 246, the winding of the relay I2, conductors 241 and 248, a contact element 250 of the relay 12, a conductor 252, the contact element I6, and the conductor 230 to the conductor 34. The contact element 66 of the relay I0 controls an energizing circuit for the coil 2! extending from the conductor 34 through the conductor 232, the contact element 68 of the relay I0, conductors 234 and 254, the winding of the relay 2M, and conductors 239 and 233 to the conductor 32.

The timing element 201 has a winding 256 which is controlled by the contact element 2I0 in left hand position in a circuit which extends from the conductor 32 through the conductor 238, the contact element 2I0, a conductor 258, the winding 256, a conductor 250, the contact element 262 which is actuated by the circuit breaker 4, and a conductor 264 to the conductor 34. The timer element winding 256 is thus energized While the circuit breaker 4 is in closed circuit position, and the contact element 2I0 is in circuit closing position. After the time interval for which the timing device 22 is adjusted, its contact element 263 will be moved to circuit closing position to close an energizing circuit for the coil 2I2 which extends from the conductor 32 through the conductors and 239, the contact element 208, a conductor 268, the coil 222, a conductor 2%, the contact element 2555, a conductor 212, a contact element 214 which is actuated by the circuit breaker 4, and conductors 216 and 264 to the conductor 34.

An overload or other suitable protective relay 218, connected to the conductors 28 and 39 to respond to an overload or other fault such that is is desired to trip the circuit breaker 4, will close an energizing circuit for the trip coil 8 of the circuit breaker 4 which extends from the conductor 32 through a conductor 286, a contact element 282 of the relay 218, a conductor 284, the winding of the tripping coil 8, a conductor 286, the contact element I02, and conductors 288, 216, and 264 to the conductor 34.

Under normal conditions, the energizing circuit for the relay i2 which will pick it up and allow it to close its own holding circuit iscontrolled by the contact element 252 which is actuated by the circuit breaker 4. This circuit extends from the conductor 32 through the conductors 238, 239, and 2-10, the contact element in the right-hand circuit closing position, the conductors 242 and 244, the rectifier 18, the conductor 245, the resistor 225, the winding of the relay l2, the conductors 241, 228, and 290, the contact element 252 in back contact position, and conductors 276 and 264 to the conductor 34.

Another ener izing circuit for the tripping coil 8 is controlled by a manually operable circuit control device 29! extends from the conductor 32 through the conductors 292 and 294, a contact element 296 of the circuit control device 291, conductors 298 and 284, the winding of the trip coil 8, the conductor 286, the contact element Hi2, and the conductors 288, 216 and 264 to the conductor 34. The actuation of the circuit control device 2 9i will also move the contact element 225 to open circuit position.

A contact element .308 actuated by the circuit control device H6 is provided to complete an energizing circuit for the relay l2 when the circuit breaker 4 opens in the event that the contact element 209 is not in the right-hand circuit closing position when the system is placed into operation by the actuation of the circuit breaker control device 216.

In the operation of the embodiment of the invention of Fig. 3, when it is desired to place the system in operation, the circuit control device 2i6 may be manually actuated to energize the relays ill and 12. The closing coil 5 will be energized as a result of the actuation of the relay l0, and the coil 2M will move the contact elements 209 and 2 ID to the lefthand circuit closing position. Vfhen the circuit breaker closes, the contact element 262 will move into position to close the energizing circuit of the winding B of the timing element to initiate its operation, and the contact element i5 will move to open circuit position to open the holding circuit of the relay 2. The relay 12 will be maintained energized, however, by the discharge of the condenser I8 through the winding of the relay l2, and the relay I0 and the closing coil 6 will be maintained energized until relay [2 is released after the time delay caused by the discharge of the condenser 58 through the winding of the relay 12. After the time interval for which the timing device 22 has been adjusted has elapsed, the contact element 265 thereof will be actuated to circuit closing position to energize the coil 212, which, in turn, will move the contact elements 209 and 218 to the right-hand position.

Should the circuit breaker 4 be tripped by the protective relay 218, the energizing circuit for the relay l2 will be closed by the contact element 262 on the breaker, and the relay l2 will pick up to energize the relay I 0 to thereby immediately energize the closing coil 6 to close the breaker. The energization of the relay [0 will energize the coil 2M to cause the contact element 209 to open the energizing circuit for the relay l2, and if the circuit breaker trips again immediately before the timing device 22 has closed its contact element 266, the timing device will be deenergized by the movement of the contact element 282 from front contact position, and there will be no further movement of the contact element 266 to again energize the coil 212 and cause the contact element 208 to close the energizing circuit for the relay [2. The circult breaker 4 will thus be locked out until it is again placed into operation manually by the actuation of the circuit control device 2l 8.

It is to be understood that the relays H0 and I40 of Figs. 1 and 2 respectively are merely illustrative of one type of protective relay and that contact elements of protective relays such as the fault relay 218 of Fig. 3 may be employed instead of or in addition to the relays H0 and I40 to perform the function of controlling the circuits controlled by the relays H0 and H0.

Thus, it will be seen that we have provided a circuit breaker control system which shall function to so control a circuit breaker as to positively close and latch the breaker and which shall be simple and efficient in operation and inexpensive to manufacture, install, operate, and maintain.

In compliance with the requirements of the patent statutes, we have shown and described herein preferred embodiments of our invention. It is to be understood, however, that the invention is not limited to the precise constructions shown and described but is capable of modification by one skilled in the art, the embodiments herein shown being merely illustrative of the principles of our invention.

We claim as our invention:

1. In a control system for a circuit breaker having closing means, a first relay for energizing said breaker closing means, a second relay for energizing said first relay, means including circuit means normally energizing said second relay, means responsive to the closing of the breaker for opening the energizing circuit for the second relay, and energy storing means connected in circuit with the second relay for automatically delaying the release of the second relay when its energizing circuit is opened.

2. In a circuit breaker closing system, a. first relay for energizing the closing means of the breaker, a second relay for energizing said first relay, means including circuit means normally energizing said second relay, means responsive to the closing of the breaker for opening the energizing circuit for the second relay, and a, capacitor means connected in shunting circuit relation with the winding of the second relay to thereby delay the release of the second relay when its energizing circuit is opened.

3. In a circuit breaker control system, a first relay connected to energize the closing means of the circuit breaker, a second relay, a circuit control device, an energizing circuit for said first relay including the circuit control device and a front contact element of the second relay, means including an energizing circuit normally energizing the second relay, said energizing circuit for the second relay including a back contact element actuated by the closing mechanism of the circuit breaker, and a capacitor connected in shunting relation with the winding of the second relay to thereby delay the release of the second relay after its energizing circuit has been opened by the operation of the circuit breaker closing mechanism.

4. In a circuit breaker control system, a first relay connected to energize the closing means of the circuit breaker, a second relay and a third relay, an energizing circuit for said first relay including a front contact element of said second relay and a front contact element of said third relay, a first energizing circuit for the second relay including a back contact element of the third relay, a second energizing circuit for the second relay including a front contact element of the second relay and a back contact element actuated by the closing mechanism of the circuit breaker, a control contact device, a first energizing circuit for the third relay including said control contact device, a second energizing circuit for the third relay including a front contact element of the third relay, and means for automatically delaying the release of the second relay after its energizing circuit has been opened by the operation of the circuit breaker closing mechanism.

5. In a circuit breaker control system, a first relay connected to energize the closing means of the circuit breaker, a second relay and a third relay, an energizing circuit for said first relay including front contact element of said econd relay and a front contact element of said third relay, a first energizing circuit for the second relay including a back contact element of the third relay, a second energizing circuit for the second relay including a front contact element of the second relay and a back contact element actuated by the closing mechanism of the circuit breaker, a control contact device, a first energizing circuit for the third relay including said control contact device, a second energizing circuit for the third relay including a front contact element of the third relay, and a capacitor c0I1- nected in shunting circuit relation with the winding of the second relay to thereby delay the release of the second relay after its energizing circuit has been opened by the operation of the circuit breaker closing mechanism.

6. In a circuit breaker control system, a first relay, an energizing circuit for the closing means of the circuit breaker including a front contact element of the first relay, a second relay, and a third relay, a first energizing circuit for the second relay including a back contact element actuated by the circuit breaker and a contact element actuated to open circuit position by the energization of the third relay, a second energizing circuit for the second relay including a front contact element of the second relay, a back contact element actuated by the circuit breaker closing mechanism and a back contact element actuated to open circuit position by the energization of the third relay, an energizing circuit for the first relay including a front contact element of the second relay, an energizing circuit for the third relay including a front contact element the first relay, means responsive to the actuation of the third relay for causing reclosure of the part of the energizing circuits for the second relay which is opened by the third relay a predetermined time after the actuation of the third relay, and means for automatically delaying the release of the second relay after its, energizing circuit has been opened by the operation of the circuit breaker closing mechanism.

7. In a circuit breaker control system, a first relay, an energizing circuit for the closing means of the circuit breaker including a front contact element or the first relay, a second relay, and a third relay, a first energizing circuit for the second relay including a back contact element actuated by the circuit breaker and a contact element actuated to open circuit position by the energization of the third relay, a second energizing circuit for the second relay including a front contact element of the second relay, a back contact element actuated by the circuit breaker closing mechanism and a back contact element actuated to open circuit position by the energizaticn of the third relay, an energizing circuit for the third relay including a front contact element of the first relay, means responsive to the actuation of the third relay for causing reclosure of the part of the energizing circuits for the second relay which is opened by the third relay a predetermined time after the actuation of the third relay, and capacitor means connected in shunting circuit relation with the winding of the second relay to thereby delay the release of the second relay after its energizing circuit has been opened by the energization of the third relay.

8. In a circuit breaker closing system, a first relay for energizing the closing means of the breaker, a second relay for energizing the first relay, a normally closed direct current energizing circuit for the second relay including a resistor, a capacitor connected in shunting relation with the part of the energizing circuit for the second relay which includes the second relay winding and the resistor, and means responsive to the closure of the breaker for opening the energizing circuit for the second relay.

MAURICE E. REAGAN. GUY W. CHAMPNEY. 

